1. Field
The claimed invention relates to communications of computer networks. More specifically, it relates to a method and system for prepaid billing for wireless mobile services in communications networks.
2. Description of Related Art
Today a wide array of “special” or enhanced telecommunications services (“services”) are available to subscribers. Telecommunications networks enable these services using “signals” or signaling messages in addition to the voice or data that compose the conversation between the calling party and the called party. These signals monitor the status of the lines, indicate the arrival of incoming calls, and carry the information needed to route the voice or other data through the network. In out-of-band signaling, these signals are carried on a separate signaling network, and are used to control the switches in the circuit-switched network for setting up, tear down, and maintaining the circuit between the calling party and called party. Currently, Signaling System 7 (“SS7”) is the most commonly used signaling system.
Most telecommunications networks in the United States use the advanced intelligent network (“AIN”) approach in which most of the control information and call processing logic, usually referred to as “service logic,” resides in a central network location, such as a service control point (“SCP”), instead of in the multitude of switches. Further, AIN provides a set of standardized messages that may be exchanged between network elements, such as switches, and the SCP to allow for a variety of services. These standards are embodied in Bellcore's AIN Release 0.1 and AIN Release 0.2.
The call control functions in a centralized SCP simplify network management since changes made at the SCP will apply to a large number of switches. Having the call control functions in a centralized SCP also makes changing or upgrading services and adding new services much easier and reduces the problem of differences in switches from different vendors. Moreover, the centralization at the SCP and the standardized message set allows an SCP to control a large number of switches, which are referred to as service switching points (“SSPs”). Another benefit of the centralization at the SCP and the standardized message set is that the SCP may control switches manufactured by different vendors. Not only does this enable manufacturers to produce generic switches, but produce generic switches that are able to provide a wide variety of services.
In operation, the SSPs signals or queries the SCP for guidance at predefined “trigger points” in the call processing, which can occur when the SSP is attempting to originate a call or attempting to terminate a call. The query signal that passes from the SSP to the SCP may contain a set of relevant parameters, in a predefined format. Such parameters can include the calling party's telephone number and the called party's telephone number. When the SCP receives the query, it executes the appropriate service logic and consults appropriate databases to obtain the information and instructions needed to provide the intelligent network service. The SCP then sends to the SSP a response message, which may contain instructions for completing or connecting the call.
The signaling network typically includes one or more signal transfer points (“STPs”) that route the signals through the signaling network between the large number of SSPs and other network interconnected elements. When SS7 signaling is used, signals may be routed to specific network elements based on their point codes. Alternatively, signals may be routed using Global Title Translation (“GTT”), in which STPs route signals to their intended destinations without the need for point codes. In particular, when GTT is used, STPs route signals based on information contained in their payloads.
Like landline telecommunication services, many of today's wireless telecommunications networks are based on a similar signaling model. In these networks, commonly referred to a first-generation (1G) and second generation (2G) networks, switching is performed by mobile switching centers (MSCs), in which each MSC typically controls one or more base nodes or base transceiver nodes (BTSs), sometimes via one or more base node controllers (BSCs). In some networks, the functions of the MSC are integral to or integrated into the BSCs, thereby eliminating the MSC and reducing the components in a wireless network. Each BTS provides a wireless coverage area within which mobile nodes can communicate with the BTS over an air interface. The mobile nodes can be cellular, PCS telephones, or other devices. Different formats may be used for communicating over this air interface. For example, some of the commonly used formats in are Advanced Mobile Phone Service (AMPS), Time Division Multiple Access (TDMA), Global System for Mobile Communications (GSM), and Code Division Multiple Access (CDMA).
Each mobile node typically has a “home” wireless network, in which a home location register (HLR) serves as a centralized repository of information about the mobile node. Typically, the HLR contains a service profile for the mobile node; the last reported location of the mobile node; and the current status of the mobile node, such as whether it is active or inactive. The service profile indicates which enhanced services the mobile node subscribes to, including whether the user subscribes to a plan containing prepaid billing services.
Mobile nodes may identify themselves to wireless networks using one or more types of identification numbers, such as (i) a 10-digit Mobile Identification Number (MIN), which may be the dialed directory number; (ii) a Mobile Directory Number (MDN), which is typically different from its MIN; (iii) a unique 32-bit Electronic Serial Number (ESN), which is generally programmed into the mobile node.
When an MSC (or alternatively a BSC) needs to find information about a mobile node, such as where it is located or what services it subscribes to, it queries the HLR corresponding to that mobile node. For example, to determine the services or the service plan that a user subscribes to, the MSC (or alternatively a BSC) queries an OLR, which may be outside of its home network, if the mobile node is roaming. The queries are then routed to the appropriate HLR based on the mobile node's identifier, such as the MIN and/or MDN. Further, the MSC (or alternatively a BSC) may reference internal translation tables to determine which HLR to query for which MINs and/or MDNs. Alternatively, STPs may route queries to the appropriate HLR using GTT and the MIN and/or MDN.
Paralleling AIN used in wireline networks, an MSC (or alternatively a BSC) may query a Wireless Intelligent Network (WIN) SCP for call processing instructions. Like the SCP in an AIN network, these call processing instructions are typically performed when originating a call from or terminating a call to the mobile node and using trigger points set by the mobile node's service profile, which the MSC (or alternatively the BSC) downloaded from the mobile node's HLR. Moreover, an MSC (or alternatively a BSC) uses such queries to obtain the call processing instructions needed to provide enhanced telecommunications services to the mobile node. In response to such queries, the WIN SCP will typically execute the appropriate service logic and consult the mobile node's service profile to formulate the call processing instructions that the WIN SCP then sends to the MSC (or alternatively a BSC).
The Telecommunications Industry Association/Electronics Industry Association (TIA/EIA) has developed a number of interim standards containing the specifications for signaling between MSCs, BSCs, HLRs, WIN SCPs, and other network elements. One of the most common standards for wireless networks in the United States is the TIA/EIA Interim Standard 41 (“IS-41”) and the revisions thereof. The IS-41 signaling is typically run as an application on another signaling system, such as SS7. A recent revision of this Interim Standard, ANSI-41 Rev. D, which was published in July, 1997, is fully incorporated herein by reference. Furthermore, extensions to ANSI-41D or WIN triggers and WIN call processing are included in Interim Standard IS-771, which was published July, 1999, and is fully incorporated herein by reference.
Providing enhanced services in the manner noted above is acceptable for voice services for telecommunication networks, which employ an HLR or equivalent central repository that is accessible to the SS7 network. This is because the HLR controls authorization of voice services. Further, units of use in the voice networks are typically time-based. And since voice activity in the current telecommunication networks inherently involves the SS7 network, the draw down of the usage units is reported to the HLR on a regular basis so that usage may be monitored reasonably well.
Because the above-described wireless networks have their foundation in older circuit-switched or similar packet-switched technologies, transmission of video and data is quite slow, which limits the type of multimedia, video and data services that V can be used. In addition to the 2G networks, newer second-and-a-half generation (“2.5G”) network services are currently providing communication services to mobile nodes. These 2.5G networks use newer packet-switched services, which allow for increased transmission speeds for video and data as compared to 2G networks. Like the 2G networks, current 2.5G networks have similar limitations on the types of multimedia, video, and data services that can be used.
Mobile nodes may take advantage of third generation (“3G”) network services, which allow for significantly faster data rates that in turn allow for a broader range of multimedia, video and data services to be used on a roaming mobile node. The 3G networks provide services for packet-based transmission communications with the capability of providing Internet Protocol (IP) traffic, such as Mobile Internet Protocol (“Mobile IP”) traffic; symmetrical and asymmetrical data rates; multimedia services such as video conferencing and streaming video; international roaming among different 3G operating environments; and more. Typical 3G systems include packet-based transmission of digitized voice, data and video. The 3G networks encompass a range of wireless technologies, which include Code Division Multiple Access (“CDMA”), Universal Mobile Telecommunications Service (“UMTS”), Wide-band CDMA (“WCDMA”), and others.
In 3G networks, communications originating and terminating from mobile nodes may use Mobile IP to establish a voice, video and/or data call from a mobile node that has roamed from its home network to a foreign network. Mobile IP allows mobile nodes to transparently move between different Internet Protocol sub-networks (“subnets”). For a mobile node to use the services of the network, it has to connect to its home subnet. The home subnet provides access to an external network, such as the Internet, through a “home agent” that serves as the subnet's gateway router.
To register on the 3G network, the mobile node may periodically transmit “agent solicitation” messages to the home agent. The mobile node also listens for “agent advertisement” messages from the home agent. When a mobile node receives an agent advertisement message indicating that it is now on it home subnet, it registers with its home agent.
To provide services to the mobile node when the mobile node “roams,” (i.e., dynamically changes its physical location), the mobile node periodically transmits “agent solicitation” messages to other gateway routers, and also listens for “agent advertisement” messages from the other gateway routers. When a mobile node receives an agent advertisement message indicating that it is now on a foreign subnet, it registers with the foreign gateway router or “foreign agent,” and with its home agent. The registration with the foreign agent allows the mobile node to receive data on the foreign subnet. Whereas, the concurrent registration with the home agent provides an indication to the home subnet that the mobile node is not at home. This may allow for forwarding to the foreign subnet the data directed to the mobile node received on its home subnet.
As noted above, 2G and later networks provide packet data services in addition to the current voice services. Further, migration of voice services to a Voice over IP model complicates matters because the packet data networks may and most likely will become the carrier for voice traffic, in contrast to the current circuit based mechanism, where voice traffic is controlled by SS7 and/or Wireless Intelligent Network (WIN) elements.
However, there are several problems associated with establishing voice, video or data calls on 3G networks. One problem is that users currently cannot easily buy, use or replenish prepaid services, such as pre-paid calling accounts on mobile nodes on some 3G networks. Such problems occur when adapting billing systems used by the SS7, WIN or other out-of-band signaling networks to 3G networks, or the provider of the 3G networks access will not undertake providing 3G services to high-risk users.
Without prepaid billing systems, large delays in receiving payments and/or bills can result in suspension or discontinuation of a user's 3G network services. And after fees are paid, it may be difficult for users of mobile nodes on to re-establish service, when pre-paid billing systems are not implemented. Moreover, providers may have difficulty in disconnecting active users of mobile nodes when outstanding fees are owed. This difficulty is further complicated when the active users of the mobile nodes are constantly roaming from one foreign network to another because usage on each of the foreign networks may not be reported until a later date. In such case, it is possible for a user to overuse the amount of allotted network services. Conversely, users may be overcharged for actual usage if multiple network elements charger for the same service. While the aforementioned issues are common to both the data and voice services, the growth of data services and the demand for prepaid services in global markets will result in a need to satisfy these deficiencies.
Packet-data traffic in the 3G networks is typically served to wireless mobile nodes by a Packet Data Serving Node (“PDSN”). The PDSN provides the same type of call control responsibility in the packet data network that the HLR provides in the circuit voice WINs network. Unlike the HLR, however, for the mobile nodes that it serves, packet data traffic may pass through the PDSN. Being in the packet-data-traffic path allows the PDSN to directly monitor and measure the usage of the wireless prepaid service. The PDSN need not be in the packet-data-traffic path, however, because the PDSN may receive usage information from another PDSN over a PDSN to PDSN link. Further details regarding inter-PDSN transfer are provided by co-pending U.S. application Ser. No. 10/097796, filed on Mar. 14, 2002, and titled “Method and System for Re-Direction and hand-off for Pre-Paid Mobile Services in Third Generations Networks,” which is fully incorporated herein by reference.
Current 3G network models presently suffer from having no mechanism for adapting prepaid billing systems used by the SS7, WIN or other out-of-band signaling networks to data networks. Thus, it is desirable to provide a method and system to support prepaid accounting and billing services that work correctly with mobile nodes on 3G networks.